Process of detinning tin-scrap.



W. J. PHELPS.

PROCESS 0F DETINNING TIN BDBAP.

APPLICATION FILED JULY 21. 19,09.

Patented Mar. 15,1910.

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Patented Mar. 1b, 191U.

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W. J. PHELPS.

PROCESS o? DETINNING TIN SCRAP.

APPLIUATION FILED JULY 27. 190s.

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WALTER J'. PHELPS, OF BALTIMORE, MARYLAND.

PROCESS ,0F DETINNING TIN-SCRAP.

Specication of Letters Patent.

Application Bled July 27, 1909.

Patented Mar. 15, 1910.

Serial No. 509,933.

To all 'whom 'it may concern:

Be it known that I, WALTER J. PHELPS, a citizen of the United States, residing at Baltimore city and State of Maryland, have invented a new and useful Process for Detinning Tin-Scrap, of which the following is'a specification.

This invention relates to the process of recovering tin from tin-coated scraps.

It has been demonstrated that tindisntegrates when subjected to extremely low temperatures, as for instance, when rough-t in contact with liquid air.

Based upon this principle, the present process consists in subjecting the tin-coated scraps or tin bearing material to an Vextremely low temperature, while simultaneously agitating ythe scraps to cause the tin to separate from the steel or other metal coated by the tin.

In the accompanying drawings, which illustrate an improved apparatus for carrying out the process, Figure 1 is a front elevation of the apparatus. Fi 2 is a central longitudinal section thereo Fig. 3 is a transverse section. Fig. 4 is an end View drawn on a reduced scale. Fig. 5 is an enlarged sectional 4View of the combined means for discharging the refri erating medium into the tin scraps and or agitating the same.

Similar referenceeharacters are employed to designate corresponding parts throughout the views.

Referring to the drawing, A designates a cylinder mounted with itsV axis horizontal and supported on standards 1 by means of brackets 2. This c linder or drumA is com posed of inner an outer shells 3 and 4 hav" lng a non-conducting material 5 packed between them for retaining the cold. At the `top of the cylinderis a door 6 for permitting the tin scraps to be deposited in the apparatus, and at'tlie .bottom is another door 7 by means of which the tin particles recovf ered from the scraps dan be removed.

Rotatablyl mounted lin the fixed cylinder A is an inner cylinder or drum B provided with solid heads 8 which carry a. perforated cylindrical shell 9 for holding the tin Scraps. AThis cylinder B is mounted to rotate on a horizontal tubularaxle 10, and onone of is rovided with a hub 11 through 'whlch t e" axle 10 extends. The hub vis journaled in shearing 12 on one of the standards, while the opposite end of the vouter drum. After the agitation has axle is journaled in a bearing 13 on thc other standard. The hub 11 carries a large gear wheel 14 which meshes'with a pinion 15 carried by a driving shaft 16, whereby the drum B is rotated. The drum has an opening 17 normally closed by a door 18 and so arranged as to register Wlth the upper door opening of the outer drum A, sothat the scraps can be placed in the inner drum.

The tin scraps are agitated during the freezing process, and for this purpose, the axle or shaft 10 is provided with a plurality of spaced outwardly-projecting arms 19 which are preferably conical so as to readily ass through the massf of scraps contained 1n the drum B. These arms or agitators also serve as discharging nozzles for the cooling or refrigerating medium, which may be liquid air 4or some equivalent material. The shaft 10 is hollow and extending longitudinally thereof is a liquid air supply pipe 20 which has numerous perforations 21, as shown in Fig. 5, through which the liquid air passes to the nozzles 19. The shaft 1G is connected with a reservoir C containing liquid air, the supply of which is regulated by a valve 22. On the end of the axle or shaft 12 is a stulliing box 23 for preventin leakage of the coolin medium. The sha 10 is rotated indepenently of the drum B by means of a gearing consisting of a large Wheel 24 on the projecting end of the shaft 10 and with which meshes a driving inion 25. It will thus be seen that liquid air can be discharged into the drum B while the shaft rotates to agitate the tin Scraps.

In practice, the tin-bearing material is supplied to the inner drum thro h the openings at'the to of the inner an outer drums, and after t 1e doors of the openings are closed, the inner drum and agitator are rotated for effectively stirring the tin scraps 'to bring every portion of the tincoated surfaces in contact with the li uid air which is sup lied by the openin o the valve 22. This iquid air acts on 51e tin in such a wayas to destroy the cohesion between the tin particles and the sheet metal coated thereby, and the particles of tin sift through the pcrforations of the inner drum and are collected in the space at thebottom of the Pro ceeded long enough to remove the tin, the door 7 is rst opened to allow the tin to drop out into a suitable receptacle. After this is done, the inner drum 1s opened when the the material.

door thereof is at the bottom, so that the sheet metal from which the tin has been removed can be emptied from the apparatus in prepara-tion for the next charge. It will thus be seen that the detnning process can be readily carried out with an extremely simple apparatus and with substantially no loss of tin. y

Having thus described the invention, what I claim as new, and desire to secure by Letters Patent, is

1. The herein described process of recovering tin from tin scraps which consists in subjecting the tin scraps to a sutliciently low temperature to disintegrate the tin, and agitating the scraps for separating the disintegrated tin therefrom.

2. The herein described process of recovering tin from tin-bearing material, which consists in subjecting the material to a freezing medium at such temperature as to disintegrate the tin, simultaneously agi'- tating the material during the action of t e said medium, and separating the tin from 3. The herein described rocess of detinning tin scraps which consists in delivering a cooling medium to the tin scraps while agitating the same to loosen the tin coating from the scraps, and separating the loosened tin from the mass of scraps.

4. The herein described process of detinning tin scraps which consists in subjecting the scraps to the action of liquid air for loosening the tin coating from the scraps, and separating the loosened tin from the mass o scraps.

5. The herein described process of detin nin tin scraps which consists in dischar f ing iquid air into a mass of t-n scraps whiti contained in a rotatable drum, simultaneously agitating the scraps for separating the loose tin particles therefrom, and collecting the separated tin articles.

6. The herein descri ed process of recovel'in tin from tinbearing material which consists in bringing the material into contact with a freezing medium to such temperature as to disintegrate the tin, and finally separating the disintegrated tin from the ma terial.

In testimony that I claim the foregoing as my own, I have hereto affixed my signature in the presence of two witnesses.

WALTER J. PHELS. Witnesses:

JOHN H. Sloeries, EDITH L. BRowN 

